ObesityKETOWEINCT06736028
Ketogenic Diets for Weight Loss Maintenance: Impact on Energy Expenditure and Appetite in Individuals With Obesity
A study testing Diet Therapy, Calorie Restriction and Behavioral Support in people with Obesity, run by University of Alabama at Birmingham at 1 site in United States.
Trial summary
The goal of this clinical trial is to investigate whether a Ketogenic Diet (KD) can increase Total Energy Expenditure (TEE), while benefiting appetite, during weight loss maintenance in reduced-obese individuals. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Obesity
- What is being tested?
- Diet Therapy, Calorie Restriction and Behavioral Support
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 20 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Aug 2025to 30 Mar 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- BMI 30-45 kg/m2
- Both men and women
- Age between 18-65 years
- Sedentary to moderately active (<2 h/wk of moderate, structured, intentional, exercise)
Who cannot join
- Pregnancy or lactation
- Daily use of tobacco (>1 pk/wk)
- Change in weight greater than 5 lb in the previous 3 months
- Cognitive impairment
- Previous bariatric surgery
- History of eating disorder
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- Presence of any condition (e.g. DM2, PCOS, inflammatory disease, untreated thyroid disease, fluid overload states such as chronic kidney disease, congestive heart failure, or cirrhosis)
- Use of any medication (e.g., glucocorticoid, GLP-1 analogues, hormone replacement therapy) deemed to interfere with study outcomes.
- Pre-menopausal women will need to have a regular menstrual cycle (28+/-2 days) or be on hormonal contraceptives
- Fasting glucose plasma concentration >125 mg/dl and/or HbA1c > 6.4%
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Alabama at Birmingham
Birmingham, Alabama, 35294
Catia Martins, PhD, 2059347922, catia197@uab.edu
About this study
The goal of this clinical trial is to investigate whether a Ketogenic Diet (KD) can increase Total Energy Expenditure (TEE), while benefiting appetite, during weight loss maintenance in reduced-obese individuals.
Read the detailed description
The total duration of the intervention will be 10 weeks. Participants will first undergo 4 weeks of a low-energy diet (LED), aiming to induce a minimum of 5% weight loss (weight loss phase). Those who achieve at least a 5% weight loss will then be randomized (1:1) to a 6-week weight loss maintenance (WLM) diet, either a KD or an isocaloric low-fat diet, with the first 2 weeks being a gradual refeeding.
- Conditions
- Obesity
- Being tested
- Diet Therapy, Calorie Restriction, Behavioral Support
- Keywords
- Ketogenic Diet, Weight loss, Weight loss maintenance, Appetite, Energy expenditure
- Medical subject headings
- Obesity, Weight Loss
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Diet TherapyBehavioural
Participants will be provided food to meet the ketogenic diet prescription for the 6-week weight maintenance phase.
Calorie RestrictionBehavioural
Participants will follow a commercial low-energy diet and be provided with meal replacements for 4 weeks aiming to achieve a minimum of 5% weight loss.
Behavioral SupportBehavioural
Participants will meet weekly with a registered dietitian, for a 20-minute consultation throughout the entire study period (10 weeks) to increase engagement and improve adherence and retention.
Diet TherapyBehavioural
Participants will have food provided to meet the standard low-fat diet prescription for the 6-week weight maintenance phase.
| Study group | Role | What they receive |
|---|---|---|
| Ketogenic Diet | Experimental | Participants randomized to the ketogenic diet will follow a diet with 5% energy from carbohydrates, 70% from fat, and 25% from protein for 6 weeks. The first 2 of the 6 weeks weeks will be a gradual refeeding, with participants slowly withdrawing from the meal replacements used during the 4-week weight loss phase, while introducing more food. Receives: Behavioral: Diet Therapy; Behavioral: Calorie Restriction; Behavioral: Behavioral Support |
| Low-Fat Diet | Active comparator | Participants randomized to the low-fat diet will follow a diet with 50% energy from carbohydrates, 25% energy from fat, and 25% energy from protein for 6 weeks. The first 2 of the 6 weeks weeks will be a gradual refeeding, with participants slowly withdrawing from the meal replacements used during the 4-week weight loss phase, while introducing more food. Receives: Behavioral: Calorie Restriction; Behavioral: Behavioral Support; Behavioral: Diet Therapy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from baseline total energy expenditure
Total Energy Expenditure (TEE) refers to the total amount of energy (calories) your body uses in a day. Twenty-four-hour EE and RQ will be measured inside the whole room indirect calorimeter (chamber) following standard procedures
Measured: Baseline, week 6, week 10
Secondary outcomes (16)
Change in appetite ratings
Subjective appetite ratings are personal feelings or perceptions about hunger, fullness, desire to eat (DTE), and prospective food consumption (PFC) usually measured using self-reported scales ranging from "not at all" to "extremely". Subjective appetite ratings (hunger, fullness, DTE and PFC) will be measured using a validated 10cm visual analog scale which will be given to the participants inside the chamber before meals.
Measured: Baseline, week 6, week 10
Change in total body composition
Bioimpedance analysis (BIA) will be used to measure fat mass, fat-free mass, total, extra, and intra-cellular water.
Measured: Baseline, week 4, week 6, week 10
Change in total body composition
FM, bone mass, and lean body mass will be determined by dual-energy X-ray absorptiometry (iDXA instrument, GE Healthcare Lunar, Madison, WI) with the use of software version 1.5g (Lunar Corp).
Measured: Baseline, week 4, week 6, week10
Change in fasting insulin
Circulating (serum) fasting insulin will be measured using validated methods
Measured: Baseline, week 6, week 10
Change in fasting cholecystokinin
Circulating (plasma) fasting cholecystokinin will be measured by RIA.
Measured: Baseline, week 6, week 10
Change in fasting ghrelin
Circulating (plasma) fasting ghrelin concentrations will be measured by ELISA
Measured: Baseline, week 6, week 10
Change in fasting glucagon-like peptide-1
Circulating (plasma) fasting total GLP-1 will be measured by ELISA
Measured: Baseline, week 6, week 10
Change in fasting peptide YY (PYY)
Circulating (plasma) fasting PYY3-36 concentrations will be measured by ELISA
Measured: Baseline, week 6, week 10
Change in total body weight
Body weight is the total amount a person weighs when measured on a scale.
Measured: Baseline, week 4, week 6, week 10
Change in mechanical efficiency
Walking economy will be assessed using a submaximal treadmill test, performed 90 minutes after breakfast. Following a familiarization period, participant will walk on the treadmill at 2 miles/hour for 15 minutes, followed by another 15 minutes at 2.5 miles/hour.
Measured: Baseline, week 6, week 10
Change in resting energy expenditure
Resting Energy Expenditure (REE) is the amount of energy (calories) your body needs to keep working while you're at rest. Participants will enter the chamber in the morning in the fasting state. REE will be measured while the participant is in the metabolic chamber.
Measured: Baseline, week 6, week 10
Change in postprandial insulin
Circulating (serum) insulin measured before and 30, 60, 90, and 120 minutes after intake of breakfast with validated methods
Measured: Baseline, week 6, week 10
Change in postprandial cholecystokinin
Circulating (plasma) cholecystokinin measured before and 30, 60, 90, and 120 minutes after intake of breakfast with RIA.
Measured: Baseline, week 6, week 10
Change in postprandial ghrelin
Circulating (plasma) ghrelin measured before and 30, 60, 90, and 120 minutes after intake of breakfast with ELISA
Measured: Baseline, week 6, week 10
Change in postprandial glucagon-like peptide-1
Circulating (plasma) total GLP-1 measured before and 30, 60, 90, and 120 minutes after intake of breakfast by ELISA
Measured: Baseline, week 6, week 10
Change in postprandial peptide yy
Circulating (plasma) PYY3-36 concentrations measured before and 30, 60, 90, and 120 minutes after intake of breakfast with ELISA
Measured: Baseline, week 6, week 10
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Dec 2024
- Study start1 Aug 2025
- Primary completion31 Dec 2026 (estimated)
- Study completion30 Mar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ObesityStudies of the same condition, open and under way.
- More trials run by University of Alabama at BirminghamThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 20 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Alabama at Birmingham
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Catia Martins, University of Alabama at Birmingham
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06736028
- Sponsor's protocol ID
- IRB-300012956
- Other IDs
- P30DK079626
- Acronym
- KETOWEI
- Status last verified
- Apr 2026
- First submitted
- 10 Dec 2024
- Last updated
- 7 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: This project will produce demographic information, anthropometric and body composition data, energy expenditure, fat oxidation, plasma concentrations of several gastrointestinal hormones involved in appetite regulation, insulin, glucose, blood lipids, and subjective appetite feelings. Data will be obtained from bioimpedance analysis and dual-energy x-ray absorptiometry (DEXA) for body compsoiiton; ELISA, RIA and other laboratorial methods used for the quantification of hormones and metabolites, and questionnaires and visual analogue scales. Data will be collected from 20 research participants. We estimate to be generating gigabyte (.csv) amounts of data. The methodology, statistical analysis plan, and a data dictionary will also be shared. Based on ethical considerations, scientific data will be de-identified and shared at the participant level. Data will be made available in .csv format and will not require the use of specialized tools to be accessed or manipulated.
Study at a glance
From the registry record, last updated by the sponsor on 7 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Ketogenic Diets for Weight Loss Maintenance: Impact on Energy Expenditure and Appetite in Individuals With Obesity
- ClinicalTrials.gov ID
- NCT06736028
- Acronym / sponsor ID
- KETOWEI / IRB-300012956
- Conditions
- Obesity
- Keywords
- Ketogenic Diet, Weight loss, Weight loss maintenance, Appetite, Energy expenditure
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 20 participants (estimated)
- Lead sponsor
- University of Alabama at BirminghamUniversity, hospital or other
- Collaborators
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
- Study start
- 1 Aug 2025 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 30 Mar 2027 (estimated)
- First posted
- 16 Dec 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to investigate whether a Ketogenic Diet (KD) can increase Total Energy Expenditure (TEE), while benefiting appetite, during weight loss maintenance in reduced-obese individuals.
Detailed description
The total duration of the intervention will be 10 weeks. Participants will first undergo 4 weeks of a low-energy diet (LED), aiming to induce a minimum of 5% weight loss (weight loss phase). Those who achieve at least a 5% weight loss will then be randomized (1:1) to a 6-week weight loss maintenance (WLM) diet, either a KD or an isocaloric low-fat diet, with the first 2 weeks being a gradual refeeding.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Ketogenic Diet | Experimental | Behavioral: Diet Therapy, Behavioral: Calorie Restriction, Behavioral: Behavioral SupportParticipants randomized to the ketogenic diet will follow a diet with 5% energy from carbohydrates, 70% from fat, and 25% from protein for 6 weeks. The first 2 of the 6 weeks weeks will be a gradual refeeding, with participants slowly withdrawing from the meal replacements used during the 4-week weight loss phase, while introducing more food. |
| Low-Fat Diet | Active comparator | Behavioral: Calorie Restriction, Behavioral: Behavioral Support, Behavioral: Diet TherapyParticipants randomized to the low-fat diet will follow a diet with 50% energy from carbohydrates, 25% energy from fat, and 25% energy from protein for 6 weeks. The first 2 of the 6 weeks weeks will be a gradual refeeding, with participants slowly withdrawing from the meal replacements used during the 4-week weight loss phase, while introducing more food. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- BMI 30-45 kg/m2
- Both men and women
- Age between 18-65 years
- Sedentary to moderately active (<2 h/wk of moderate, structured, intentional, exercise)
Key exclusion criteria (10 listed)
- Pregnancy or lactation
- Daily use of tobacco (>1 pk/wk)
- Change in weight greater than 5 lb in the previous 3 months
- Cognitive impairment
- Previous bariatric surgery
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Diet TherapyParticipants will be provided food to meet the ketogenic diet prescription for the 6-week weight maintenance phase. | Behavioural | Ketogenic Diet |
| Calorie RestrictionParticipants will follow a commercial low-energy diet and be provided with meal replacements for 4 weeks aiming to achieve a minimum of 5% weight loss. | Behavioural | Ketogenic Diet, Low-Fat Diet |
| Behavioral SupportParticipants will meet weekly with a registered dietitian, for a 20-minute consultation throughout the entire study period (10 weeks) to increase engagement and improve adherence and retention. | Behavioural | Ketogenic Diet, Low-Fat Diet |
| Diet TherapyParticipants will have food provided to meet the standard low-fat diet prescription for the 6-week weight maintenance phase. | Behavioural | Low-Fat Diet |
Primary outcome
Change from baseline total energy expenditure
Time frame: Baseline, week 6, week 10
Total Energy Expenditure (TEE) refers to the total amount of energy (calories) your body uses in a day. Twenty-four-hour EE and RQ will be measured inside the whole room indirect calorimeter (chamber) following standard procedures
16 secondary outcomes
Change in appetite ratings
Time frame: Baseline, week 6, week 10
Change in total body composition
Time frame: Baseline, week 4, week 6, week 10
Change in total body composition
Time frame: Baseline, week 4, week 6, week10
Change in fasting insulin
Time frame: Baseline, week 6, week 10
Change in fasting cholecystokinin
Time frame: Baseline, week 6, week 10
Change in fasting ghrelin
Time frame: Baseline, week 6, week 10
Change in fasting glucagon-like peptide-1
Time frame: Baseline, week 6, week 10
Change in fasting peptide YY (PYY)
Time frame: Baseline, week 6, week 10
Change in total body weight
Time frame: Baseline, week 4, week 6, week 10
Change in mechanical efficiency
Time frame: Baseline, week 6, week 10
Change in resting energy expenditure
Time frame: Baseline, week 6, week 10
Change in postprandial insulin
Time frame: Baseline, week 6, week 10
Change in postprandial cholecystokinin
Time frame: Baseline, week 6, week 10
Change in postprandial ghrelin
Time frame: Baseline, week 6, week 10
Change in postprandial glucagon-like peptide-1
Time frame: Baseline, week 6, week 10
Change in postprandial peptide yy
Time frame: Baseline, week 6, week 10
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Apr 2026.
- Individual participant dataSharing planned: Yes. This project will produce demographic information, anthropometric and body composition data, energy expenditure, fat oxidation, plasma concentrations of several gastrointestinal hormones involved in appetite regulation, insulin, glucose, blood lipids, and subjective appetite feelings. Data will be obtained from bioimpedance analysis and dual-energy x-ray absorptiometry (DEXA) for body compsoiiton; ELISA, RIA and other laboratorial methods used for the quantification of hormones and metabolites, and questionnaires and visual analogue scales. Data will be collected from 20 research participants. We estimate to be generating gigabyte (.csv) amounts of data. The methodology, statistical analysis plan, and a data dictionary will also be shared. Based on ethical considerations, scientific data will be de-identified and shared at the participant level. Data will be made available in .csv format and will not require the use of specialized tools to be accessed or manipulated.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Diet Therapy, Calorie Restriction and Behavioral Support in people with Obesity, run by University of Alabama at Birmingham at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 7 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Catia Martins, PhD (205-934-7922, catia197@uab.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from baseline total energy expenditure (time frame: Baseline, week 6, week 10). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Apr 2026.